Part:BBa_K554007

Hemolysin B - HlyB

HlyB is part of the hemolysin secretion system ([http://2011.igem.org/Team:UNICAMP-EMSE_Brazil/Project#Device_3:_Secretion_system Device 3, Protein Secretion System]), very important to export the proteins produced inside bacteria and that must act in targets outside (such as IL-12 and IL-10). HlyB acts as a ATP-binding cassette, and recognizes the substrate via its secretion signal (like HlyA) and is responsible for the specificity of the secretion system process. This system is composed of 4 essential parts: the C-terminal signal sequence of alpha-hemolysin (HlyA, which will be linked to the export target protein), the two specific translocator proteins HlyB and HlyD and the outer membrane protein [BBa_K554009 TolC].

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 1301
  Illegal BglII site found at 1964
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 231
  
• 1000
  COMPATIBLE WITH RFC[1000]

Usage and Biology

You can see a representation of this device acting in the schema below:

Representation of device 3, the protein secretion system, in a Jedi bacteria that contains Device 1 (Adrenaline sensor/IL-12 producer). To export a protein, the bacteria must have the HlyD, HlyB and TolC proteins and the target protein must have a signal sequence (HlyA tail). In this case, the target protein to be secreted is IL-12.

Three-dimensional structure representation

You can find below a tridimensional structure of ATP-binding domain of hemolysin B from Escherichia coli (retrieved from PDB 1MT0 (Schmitt et al. 2003)) solved by X-ray crystallography at 2.5 A resolution. This is a jmol applet, in which you can interactively see the protein structure of the QseC cytoplasmic domain:

References

Schmitt, L., Benabdelhak, H., Blight, M.A., Holland, I.B., Stubbs, M.T.Crystal structure of the nucleotide-binding domain of the ABC-transporter haemolysin B: identification of a variable region within ABC helical domains.Journal: (2003) J.Mol.Biol. 330: 333-342 [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=12823972 Link to PubMed]